CVE-2016-6127 in Request Tracker
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Request Tracker (RT) 4.x before 4.0.25, 4.2.x before 4.2.14, and 4.4.x before 4.4.2, when the AlwaysDownloadAttachments config setting is not in use, allows remote attackers to inject arbitrary web script or HTML via a file upload with an unspecified content type.
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Analysis
by VulDB Data Team • 10/21/2019
The CVE-2016-6127 vulnerability represents a critical cross-site scripting flaw in the Request Tracker (RT) ticketing system that affects multiple version branches including 4.x before 4.0.25, 4.2.x before 4.2.14, and 4.4.x before 4.4.2. This vulnerability specifically manifests when the AlwaysDownloadAttachments configuration setting is not enabled, creating a dangerous attack vector for remote threat actors. The flaw enables malicious users to execute arbitrary web scripts or HTML code through crafted file uploads, potentially compromising the security of entire ticketing systems that rely on RT for issue tracking and management. The vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is classified as a fundamental web application security weakness that allows attackers to inject client-side scripts into web pages viewed by other users. This particular implementation vulnerability demonstrates how improper input validation and output encoding can create persistent security risks in enterprise ticketing systems where users frequently upload attachments and interact with web interfaces.
The technical exploitation of this vulnerability occurs through the manipulation of file upload mechanisms within the RT system when the AlwaysDownloadAttachments setting is disabled. Attackers can craft malicious files with unspecified content types that bypass normal validation checks, allowing them to inject HTML or JavaScript code directly into the system. When other users view these malicious attachments through the web interface, the injected scripts execute in their browsers, potentially leading to session hijacking, credential theft, or further exploitation of the compromised systems. The vulnerability's impact is particularly severe because it leverages the legitimate file upload functionality of the system, making it difficult to distinguish between benign and malicious uploads without proper validation controls. The attack chain typically involves uploading a file with a carefully crafted content type or file extension that the system processes without adequate sanitization, followed by the execution of malicious code when the attachment is viewed by another user. This attack pattern aligns with the ATT&CK technique T1059.007 for Command and Scripting Interpreter, specifically targeting web-based scripting execution through user interface interactions.
The operational impact of CVE-2016-6127 extends far beyond simple script injection, as it can compromise entire organizational security infrastructures that depend on RT for managing critical support tickets and issue tracking. Organizations using affected RT versions face significant risks including unauthorized access to sensitive information, potential data exfiltration, and the possibility of attackers establishing persistent access through session manipulation or credential theft. The vulnerability particularly affects enterprise environments where ticketing systems serve as central hubs for communication and collaboration, making them prime targets for attackers seeking to gain access to broader network resources. Security teams must consider the cascading effects of such vulnerabilities, as compromised ticketing systems can provide attackers with insights into organizational processes, user credentials, and system configurations. The attack surface is further expanded when considering that RT systems often contain sensitive data including customer information, system logs, and internal communications, making successful exploitation particularly damaging. Organizations should also recognize that this vulnerability can be combined with other attacks to create more sophisticated compromise scenarios, such as using the XSS payload to redirect users to phishing sites or to execute additional malicious code through browser-based attack vectors. The remediation process requires immediate patching of affected versions, but organizations must also implement additional security controls including input validation, output encoding, and regular security assessments to prevent similar vulnerabilities from emerging in other system components.